1. Field of the Invention
The present invention relates to an intaglio printing press having an ink recovery function.
2. Description of Related Art
Intaglio printing is a printing method using a printing plate (intaglio printing plate) having recesses formed in printing image areas with respect to non-printing image areas. After the entire printing plate is filled with ink, the ink on the non-printing image areas is wiped off to leave the ink only in the printing image areas. Thereafter, paper is forced directly to the printing plate under heavy pressure to transfer the ink remaining in the printing image areas onto the paper.
An example of an intaglio printing press used for this type of intaglio printing is shown in FIG. 10. Arrows in the figure indicate rotation directions of cylinders and rollers.
Reference numeral 101 designates an intaglio plate cylinder with which an impression cylinder 102 is in contact. Around the intaglio plate cylinder 101, an intaglio printing plate is mounted. This intaglio printing plate is formed of planes as non-printing image areas and recesses as printing image areas. On one side of the intaglio plate cylinder 101, a plurality of inking units 103 are provided. Pattern rollers 104, which are form rollers of the respective inking units 103, are in contact with the intaglio plate cylinders 101. Ink fountain rollers 106 of ink fountains 105 which reserve inks of different colors are in contact with the respective pattern rollers 104. On the surface of each of the pattern rollers 104, convexly patterned portions are formed such that each color of the ink to be supplied to the corresponding pattern roller 104 is supplied only to areas of the intaglio printing plate where each color of the ink should be supplied. Specifically, each of the ink fountain rollers 106 transfers the ink only to the convexly patterned portions of the corresponding pattern roller 104, and the ink is transferred from the patterned portions to predetermined positions (printing image areas and non-printing image areas) of the intaglio printing plate.
Before a contact point of the intaglio plate cylinder 101 and the impression cylinder 102, a wiping unit 107, as an ink removing unit, is provided on the side of the intaglio plate cylinder 101, and a wiping roller 108 of the wiping unit 107 is in contact with the intaglio plate cylinder 101. The surplus (or excessive) ink on the intaglio printing plate is wiped off by the wiping roller 108. Specifically, the ink remains only in the printing image areas of the intaglio printing plate. The wiping roller 108 is immersed in washing liquid 110 within a washing chamber 109, or the surface thereof is sprayed with the washing liquid. The ink wiped off is washed away by an unillustrated washing unit which is in contact with the wiping roller 108 in the washing liquid 110.
Meanwhile, a sheet of paper 111 is fed between the intaglio plate cylinder 101 and the impression cylinder 102. The sheet of paper 111 is pressed against the intaglio printing plate of the intaglio plate cylinder 101 under strong pressure by the impression cylinder 102, and the ink in the printing image areas of the intaglio printing plate is transferred onto the sheet of paper 111. The printed paper after this intaglio printing is delivered by a delivery unit 112.
As described above, the surplus ink of the ink supplied to the intaglio printing plate is wiped off by the wiping roller 108. However, the surplus ink is not always wiped off completely only by the wiping roller 108. Therefore, as disclosed in the Japanese Patent Laid-Open No. Heisei 2-42070, a pre-wiping roller is provided upstream of the wiping roller 108 and may wipe off the surplus ink before the wiping roller 108 does so.
Since quite a large quantity of the ink is wiped off by the wiping roller 108, recovery of such ink has been demanded. Particularly, recovery of a color of ink which is used in a large quantity and of an expensive ink has been demanded.
However, when the wiping roller 108 is immersed in the washing liquid to remove the ink, the ink is mixed into the washing liquid. Therefore, the ink is no longer seperatable and recoverable, and thus it has been discarded. The Japanese Patent Laid-Open No. Heisei 2-42070 suggests carrying out the pre-wiping only, and it is thus considered that the pre-wiped ink has also been discarded.
Thereupon, recovery of the ink has been conducted before the wiping roller 108 wipes off the ink. Currently, the recovery of the ink is carried out by an operator using a spatula or the like to return the ink, which is transferred from the surface of the intaglio printing plate to the surface of the roller, into the ink fountain.
However, since the recovery of the ink is manually operated by the operator using the spatula, the operator sometimes drops the scraped ink or returns the ink into an ink fountain for a different color of ink after collecting the ink in a saucer. When the recovered ink is returned into an ink fountain for a different color of ink, a large quantity of spoilage of paper occurs.